The invention relates to a method of joining metallic profile components, more particularly bicycle frame members, of which at least one member is matched at the joint to the shape of the other member so as to form a gap with substantially equal width, then brazing them together.
As a rule, bicycle frames consist of a number of tubes which are inserted into lugs and are brazed thereinto, the lugs in turn being fitted into bearing housings for the headset and for the bottom-bracket bearing and into the clamping piece for the saddle support. The cost of fabricating the bearing housings and the clamping piece is high because the lugs must be shaped during a drawing process using ductile material. Since the strength of a joint depends on the accuracy of the brazing joint, it is necessary to maintain close tolerances for the tubes and the lugs. However, close tolerances result in high costs. Because of the close tolerances to be maintained, the cost of assembling the individual members is also high and it is necessary to round off the tube ends for easier insertion. The lugs have the additional drawback that they need a substantially long heating and brazing time, as well as a great amount of solder and flux to produce a satisfactory joint. The long heating over a comparatively large area during the brazing of the lugs results in warping and heavy scaling of the frame. Therefore, it is necessary to securely clamp the individual frame members together and to subsequently readjust them.